Module 13.01 Key Concepts: Just-in-Time / Lean Principles
As indicated earlier, Just-in-time (JIT) approaches to manufacturing planning and control result in change for both manufacturing practices and Manufacturing Planning and Control execution. JIT usually also requires fundamental change it the manufacturing layout / environment. We will look at some of these areas in more depth here.
From a Production Layout perspective, JIT strives to reduce waste due to movement. Large lots and long production lines with single-purpose machinery are being replaced by smaller flexible cells. These work cells often employ U-shaped for shorter paths and improved communication. Group technology concepts are used to help design these cells effectively. Work Cells are further designed to be rearranged as volume or designs change. This type of arrangement is applicable in office environments as well as production settings. Cellular layouts facilitate both product and process improvement.
Production layout also impacts and places special requirements on employees. Employees may be cross trained for flexibility and efficiency. In addition, improved communications facilitate the passing on of important information about the process. With little or no inventory buffer, getting it right the first time is critical
Reduced space requirements in facilities significantly impacts inventory requirements. With reduced space, inventory must be in very small lots. Units are always moving because there is no / minimal storage.
problems. As Shingo says “Inventory is evil”. Average inventory can be reduced by elimination of scrap and ensuring quality in product and processes.
signals may used, but the system is still called a kanban.
The Toyota Production System often serves as the benchmark for JIT / Lean Operations. It provides a series of standard work practices.
- Work shall be completely specified as to content, sequence, timing, and outcome
- Internal and external customer-supplier connection are direct
- Product and service flows must be simple and direct
- Any improvement must be made in accordance with the scientific method at the lowest possible level of the organization
JIT is often linked with the overall philosophy of Lean principle in an organization. Lean operations focus is typically broader than JIT in that it is externally focused on the customer. It starts with understanding what the customer wants and then optimizes the entire process from the customer’s perspective. From a organizational perspective, transitioning to a lean system can be difficult. Lean systems tend to have the following attributes: they use JIT techniques; build systems that help employees produce perfect parts and reduce space requirements. Lean system further tend to:
- Develop partnerships with suppliers
- Educate suppliers
- Eliminate all but value-added activities
- Develop employees
- Make jobs challenging
- Build worker flexibility
Lean initiatives are also quite supportive of the sustainability focus of a firm. The overall goal is to maximize resource use and economic efficiency on the one hand and, at the same time, focus on issues outside the immediate firm. Driving out waste is the common ground between the two.
- Suppliers
- Layouts
- Inventory
- Scheduling